Method and apparatus for magnetic separation of particulates from liquids

ABSTRACT

The magnetic separator has a tank with a pair of dual conveyor chains, spaced apart, at opposite sides of the tank. A plurality of frames with spaced apart magnetic rods are suspended from the conveyor chains in a manner allowing the frames to swivel and always hang vertically as the chains traverse their endless path. The liquid in the tank flows through the frames and ferrous particles are attracted to the magnetic rods. The rods are cleaned and the ferrous particles removed at a wiping station. Each frame has a scraping edge which contacts the bottom of the tank and drags out the non-magnetic particulate which has separated from the liquid.

BACKGROUND OF THE INVENTION

This invention relates to a method and apparatus for magneticallyseparating ferrous particulates or particles from metal working coolantsand parts washing fluids.

Some industrial processing liquids such as machine or metal workingcoolants are processed through magnetic rod separators typicallyembodying dual conveyor chains, spaced apart, with the magnetic rodssuspended between them. The rods are arranged in a parallel fashion witha small gap between them for the fluid to flow through. The conveyorchains describe a loop within the tank wherein the fluid must travelfrom outside the loop to the inside of the loop as it flows to theoutlet located in the tank. With the prior art separators, the fluidpasses through the magnetic rods as desired but the fluid merely passesthrough them a single time or pass. It is appreciated that the fluid hasa propensity to flow only through the magnetic rods closest to theinlet.

SUMMARY OF THE INVENTION

Unlike other magnetic separators, the method, process and apparatus ofthe present invention utilizes spaced apart magnetic rods mounted inframes which attract the ferrous particles of the liquid being treated.Each frame is suspended between a pair of conveyor chains located in atank in a manner allowing each frame to swivel and always hangvertically in the tank as the chain follows its endless path. The framesspan the width of the tank such that the liquid must flow through themagnetic gaps of the frames as the liquid travels from the inlet of thetank to the outlet.

By increasing the length of the tank, many additional frames can besuspended in the flow providing a “multi-pass” effect rather than a“single” effect as in the prior art. The frames travel the length of thetank, with each frame being designed to contact and to scrape the floorof the tank and to drag out the particulate that is non-magnetic. Theliquid or coolant is forced to flow through all of the magnetic rodslocated in the tank, not merely the frame closest to the inlet as is thesituation with the prior art.

A feature of the present invention is that the magnetic separatorincludes a number of major components including a main tank whichreceives the metal working coolants or part washing fluids and where themagnetic frames are suspended. The tank has an inclined wall, forming adrag ramp where the non-ferrous particulate is dragged out from the tankby the action of the moving frames. The frames are attached to anendless chain conveyor that conveys the frames through the main tank, upthe drag ramp to a wiping station where the frames are wiped to removethe ferrous particles or particulate.

Another feature of the present invention is that the magnetic frameseach has a plurality of magnetic rods or tubes which are spaced apartand arranged parallel to each other with small gaps between them. Therods or tubes are mounted in a frame which transports them through thetank. The frame is designed, as mentioned previously, with a scrapingedge that contacts the floor of the tank when the frame is traversingthe lower tank track.

Still another feature of the present invention is the provision of thetrack system which guides the conveyor chains through the tank and upthe drag ramp. The track system includes an upper tank track, a lowertank track, an upper ramp track and a lower ramp track. In addition, thelower tank and ramp tracks are provided with an upper guide track whichmaintains the conveyor chains on the lower tank and ramp tracks as theconveyor chains proceed in an endless path.

A further feature of the present invention is the provision of the wiperblades at a wiping station located at the upper end of the drag ramp.The wiper blades are spring loaded in a closed position. As a magneticframe travels up the ramp, the frame contacts a trip lever which opensthe wiper blades. After the frame top has passed the trip lever, theblades close on the magnetic rods and wipe off the collected ferrousparticulate. When the bottom end of the frame approaches, a protrusionon the frame made for this purpose contacts the trip lever and theblades again open to allow the bottom of the frame to pass.

A still further feature of the present invention is the provision of awiper cam which is attached to the trip lever. When the trip lever isrotated by the moving frame, the cam action forces the blades apart.After the frame has cleared, the springs close the wiper blades.

Another feature of the present invention is that as each frame exits thewiper station or wiper blades, it is necessary to reroute the bottom ofthe frame from the lower ramp track to the upper ramp track. This isaccomplished by providing a novel switch track which has a stationarytrack part and a pivoted or movable track part. The movable part of theswitch track is hinged to allow it to be lifted by the frame as theframe swings upward and forward. Once the frame has cleared the switchtrack, the pivoted track then falls back due to gravity and forces theframe to follow the upper ramp track as the conveyor chains return tothe main tank.

Still another feature of the present invention is that the magneticseparator is not required to operate continuously. As the frames areconveyed through the tank, periodically a frame on the upper tank trackis positioned directly above the frame on the lower tank track. Allowingthe frames to dwell in this position is desirable in that it presents noalternative path for the fluid to flow except through the magnetic gapsof the frames. The apparatus may be provided with suitable controls thatcan be used to allow the conveyor to stop in this desirable position forlong periods of time while the magnetic rods attract the fluid borneferrous particulates or particles. Then, on a time basis, the conveyerdrive will advance one frame through the wiper mechanism and thereafterthe frame will strike a limit switch which halts the conveyor once againin this desirable dwell position.

It is a further feature of the present invention to provide a magneticseparator or apparatus which is economical to manufacture, efficient tooperate and is environmentally acceptable in the treatment ofmetalworking coolants and parts washing fluids.

IN THE DRAWINGS

FIG. 1 is a diagrammatic view of a prior art magnetic separator wherethe dirty coolant makes a single pass through the magnetic bars;

FIG. 2 is an isometric view of the magnetic separator, with parts brokenaway to illustrate the dual conveyor chains supporting and moving aplurality of frames carrying magnetic rods through the dirty coolant;

FIG. 3 is a side elevational view of the magnetic separator, with theside of the separator tank removed to expose the interior thereof;

FIG. 4 is a sectional view, with parts broken away, taken on the line4—4 of FIG. 3;

FIG. 5 is a transverse view, with parts broken away, of the wiper bladesillustrated in an open position and taken on the line 5—5 of FIG. 3;

FIG. 6 is a view similar to FIG. 5, illustrating the wiper blades in aclosed position;

FIG. 7 is a side view of the magnetic frame;

FIG. 8 is a fragmentary elevational view of the magnetic frame lookingin the direction of arrow 8 of FIG. 7;

FIG. 9 is a bottom view of the magnetic frame, rotated 90°, looking inthe direction of arrows 9—9 of FIG. 7;

FIG. 10 is a sectional view through the tube or rod support taken on theline 10—10 of FIG. 9;

FIG. 11 is a fragmentary sectional view taken on the line 11—11 of FIG.8;

FIG. 12 is a fragmentary perspective view of the tube support formingthe lower end of the frame and illustrating the nipples which fit intothe lower ends of the tubes of the magnetic frame to close the tubes;

FIG. 13 is a fragmentary elevational view of the tube support, nipplesand tubes;

FIG. 14 is a fragmentary view of the drive end of the conveyor chains,illustrating a magnetic frame moving up the ramp in the direction ofarrow A, with the top of the frame approaching the switch track;

FIG. 15 is a view similar to FIG. 14, illustrating the bottom of themoving magnetic frame rising from the lower ramp track;

FIG. 16 is a view similar to FIGS. 14 and 15, illustrating the lower endof the moving magnetic frame lifting the pivoted switch track and movingthrough the opening;

FIG. 17 is a view similar to FIGS. 14–16, illustrating the pivotedswitch track returning to a closed position as a result of gravity, withthe moving frame having cleared the opening traveling on the upper ramptrack and moving down the upper ramp track in the direction of arrow B;

FIG. 18 is fragmentary view of the cam and trip lever for the wiperblades of FIGS. 5 and 6, showing the springs for biasing the wiperblades to a closed position; and

FIG. 19 is a view similar to FIG. 18, illustrating the wiper cam, triplever and springs in a position corresponding to the open position ofthe wiper blades.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A bar type magnetic separator of the prior art is diagrammaticallyillustrated in FIG. 1. The separator 10 includes a tank 12 having aninlet 14 and pipe 16 through which metal working coolants or other dirtyfluids or liquids enter the tank 12. Mounted in the tank 12 is anendless array of magnetic bars 18 connected to a chain drive mechanism20 driven by a drive 22. Wiper blades 24 are provided at the top of thetank 12 and through which the magnetic bars 18 move in an endless pathand where the bars 18 are wiped by the wiper blades 24. The ferrousparticles from the magnetic bars 18 are directed into a hopper 25 andare removed from the hopper 25 by an auger 26. It should be noted thatthe magnetic separator 10 is a “single” path separator wherein the fluidenters the tank 12 at the bottom and passes through the bars 18 closestto the inlet 14 into the center of the chain mechanism 20 where theliquid after a single pass exits the tank 12 through an exit tube 27.The fluid or liquid that is cleaned is directed to a clean solution tank30 from where the fluid is recirculated via the line 32 for reuse.

The magnetic separator of the present invention is designated by thenumeral 40 in FIG. 2. It consists of an elongated tank 42, a pair oftransversely spaced apart endless conveyor chains 44 and 46 and aplurality of longitudinally spaced magnetic frames 48 which aresuspended from the conveyor chains 44 and 46 and are moved by theconveyor chains through the dirty liquid coolant or parts washing fluidlocated in the tank 42.

The elongated tank 42 has a bottom wall 50, a pair of side walls 52 and54 connected to the bottom wall 50, a front wall 56 connected to thebottom wall 50 and the side walls 52, 54. The front wall 56 is locatedat one end of the tank 50 where the fluid enters the tank 42. The tank42 further includes a ramp or ramp wall 60 at the other end of the tank50 extending upwardly from the bottom wall 50 and in a direction awayfrom the front wall 56 to form an upwardly and outwardly inclined rampas best illustrated in FIG. 3. The ramp wall 60 has the edges thereofconnected to the side walls 52 and 54. The top of the tank 42 isnormally open.

An inlet 80 is provided in the end wall 56 of the tank 42 for directingliquids or coolants containing ferrous particles and other particulateinto the tank 42. An inlet baffle 82 extends between the side walls 52and 54. The baffle 82 is spaced a short distance from the inlet 80 forthe purpose of reducing the velocity of the incoming flow of the coolantand to distribute the coolant flow evenly across the width of the tank40. The baffle 82 assists in producing laminar liquid flow in the tank42. The flow through the tank 40 may be reversed in direction than thatwhich is illustrated and described.

The tank 42 has an outlet 84 which extends from an outlet trough 86located in the tank 42 above the ramp 60. The trough 86 extends betweenthe side walls 52, 54 of the tank 42 and includes a dam or weir 88 overwhich the fluid flows as it exits the tank 42. The weir 88 determinesthe height of the liquid in the tank 42.

The magnetic separator 40 includes a novel track system 90 mounted inand extending lengthwise of the elongated tank 42. The track system 90includes a lower tank track 92, a lower ramp track 94 which forms acontinuation of the lower tank track 92, an upper tank track 96 and anupper ramp track 98 which is a continuation of the upper tank track 96.The upper tank track 96 is spaced above the lower tank track 92 whilethe upper ramp track 98 is spaced above the lower ramp track 94. Theupper tank track 96 at the inlet end of the tank 48 is provided with acurved track portion 100 which is a continuation of track 96. Theendless conveyor chains 44, 46 each moves in an endless path along theupper tank track 96 around the track portion 100 and onto the lower tanktrack 92 as illustrated in FIG. 3. Thereafter the chains 44, 46 continueto be driven towards the discharge end of the tank 42 where the conveyorchains each follows its respective upper ramp track 94. A pair of chainguards 102 are spaced above the lower tracks 92 and 94 for the purposeof keeping the chains on the tracks.

The upper ends of the conveyor chains 44 and 46 are mounted on a pair ofplastic wheels or discs 104. The wheels 104 are mounted on short stubshafts 106 allowing the frames 48 to pass between the stub shafts 106.The stub shafts 106 are mounted in a manner that allows them to beadjusted to remove chain slack that develops in chains 44 and 46 overtime. Chains 44, 46 are driven by sprockets 108, 110 mounted on oppositeends of a shaft 112. The sprockets 108, 110 are drivingly connected to amotor or drive mechanism 114 as diagrammatically illustrated in FIG. 2.

With the construction of the magnetic separator 40 just described, itwill be appreciated that the pair of transversely spaced apart endlessconveyor chains 44 and 46 are movably mounted in the tank 42 and areguided by the track system 90 consisting of the tracks 92, 94, 96 and98, with the conveyor chains describing an endless loop within the tank42.

The plurality of longitudinally spaced magnetic frames 48 are mounted inthe tank 42. Each magnetic frame 48 extends transversely or across thetank 42 between the side walls 52, 54. Each magnetic frame 48 has anupper end and a lower end, with the upper end of each frame suspendedfrom the conveyor chains 44 and 46 as shown in FIG. 2.

Each magnetic bar frame 48 comprises an elongated tubular member or boxtube 120 of generally square or rectangular configuration as illustratedin FIG. 12 forming the upper end of the frame. The box tube 120 has alongitudinally extending axis 124 (FIG. 8) and a pair of parallel endsurfaces 122 which are perpendicular to the longitudinal axis 124. Theother end of the magnetic bar frame 48 includes an elongated tubesupport 126 forming the lower end of the frame 48. The tube support 126has a series of upstanding ribs 128 which are spaced apart and separatedby gaps 129. Thus, the top edge of the tube support 126 is provided witha series of alternating ribs 128 and gaps 131. The ribs 128 providesupport for the tubes or rods 130 made from non-ferrous material. Therods 130 are provided with a plurality of bar magnets 132 and polepieces 133 stacked in end-to-end abutting relationship in each of thetubes between the tubular member 120 and the tube support 126. The lowerend of each tube 130 engages a nipple or protrusion 134 which is part ofrib 128 and extends into the corresponding lower end of the tube 130 forlocating same. Each pole piece 133 is in the form of a round ferrousplate located between each pair of magnets 132. The plate or pole piece133 focuses the magnetic field as a ring around the tube 130. A plug 135is installed in both ends of each tube 130 prior to installing the tubein the frame. Plug 135 has the dual function of containing the magnets132 and pole pieces 133 and sealing the ends of the tube. Each plug 135is driven deeply enough into the tube 130 to leave a short space at theends. This space is where the nipple or protrusion 134 will fit when thetubes 130 are mounted in the frame 48.

A guide plate 136 secures the upper ends of the tubes 130 and abuts thebottom of the box tube 120 when assembled. The plate 136 has spacedapart openings 137 which are aligned with the open ends of the tubes130. The bar frames 48 further includes a pair of longitudinally spacedsupports 138 at the sides. The side supports 138 have the edges thereofattached to the box tube or tubular member 120 and to the tube support126. The tubes or rods 130 are spaced vertically apart to form gaps,equal in width to gaps 131, through which the liquid flows.

The magnetic bar frame 48 further includes a tubular pipe 142 having alongitudinal axis which is coincidental with the axis 124 of the boxtube 120. The tubular pipe 142 extends through the box tube 120 and hasend portions 144 extending beyond the end surfaces 122 of the tubularmember 120. Stop elements 140 extend over the ends of the pipe 120 andabut the end faces 122 of the box tube 120 as shown in FIG. 8. The outerend portions 144 of the tubular pipe 142 are attached to the endlessconveyor chains 44 and 46 in order to suspend the frames from theconveyor chains.

The tube support 126 is provided at the lower end thereof with a pair oftransversely spaced apart brackets 146 carrying lift pins 150 as shownin FIGS. 7–9. In addition, the tube support 126 includes at oppositeends thereof tubular guide pins 152. The elongated tube support 126 isbent or configured to form a scraper edge or blade 153 at the lower endof the frame 48 that contacts the floor or bottom wall 50 when the frame48 is traversing the lower tank track 92.

As the magnetic frames 48 are moved through the liquid or fluid to becleaned, the ferrous particles within the dirty fluid are attracted tothe magnetic rods or tubes 130 throughout the length thereof as thefluid travels through the space or gaps between the tubes 130 from theentrance end to the exit end of the tank 42. The non-ferrous particlesor particulates which are not attracted to the magnetic frames 48 settleout on the bottom of the tank 42. The frames 48 as they move through thetank 42 have the lower edges thereof 153 scraping the bottom of the tank42 and the tank ramp 60 so as to move the settled out particulates upthe ramp 60 to an exit provided in the ramp wall where the particulatesmay be collected in a hopper, not shown, and thereafter moved to aseparate facility.

It is necessary to remove from the magnetic tubes 130 the ferrousmaterial attracted thereto. This must be done prior to recirculating theframes 48 within the tank 42. There is provided at the exit or drivenend of the conveyor system a wiping station 160 which is constructed anddesigned to sequentially receive the magnetic frames 48 and to wipe theferrous particles from the magnetic tubes 130 contained within theframes.

Referring now to FIGS. 3, 5, 6, 18 and 19, there is illustrated a wipingstation 160 which is triggered by movement of the magnetic frame 48 upthe ramp 60. The wiping station 160 includes a lower wiper arm assembly162 and an upper wiper arm assembly 170. The assembly 162 includes asliding support arm 164 having the ends thereof mounted in attachmentaids 165. A lower wiper blade 166 is attached to the arm 164. The upperedge of the wider blade 166 is provided with a serrated wiper strip 167of semi-circular configuration and designed to fit around and wipe thetubes 130 of the frame 48 as it passes therethrough. The wiper strip 167is made from a flexible urethane material that can be replaced whenworn. The wiper strip 167 is bolted to the wiper blade 166 which isattached to the wiper support am 164. The upper wiper arm assembly 170includes a support arm 172 having the ends mounted in attachment aids173. Outboard of the attachment aids 173 are cam bearings 174. Thesupport arm 172 carries a wiper blade 176. A wiper strip 177corresponding to the configuration of the other wiper strip 167 is alsomade from flexible urethane material and the wiper strip 177 isreplaceable when worn. The wiper strip 167 and 177, when closed, wipethe magnetic particles from the tubes 130.

The support blades 166 and 172 each have end portions mounted in slotsprovided in the side walls 52 which permit the support blades 166 and172 to slide vertically up and down as viewed in FIGS. 5 and 6 to openand close.

The wiper arm assembly 162 includes at each side of the apparatus ashaft 180 on which is mounted a cam 182 engageable with a cam bearing orroller 174. The cam bearings or rollers 174 are provided on the ends ofthe support blades 166 and 172 and ride on the cams 182. As the cams 182rotate, the rollers 174 ride up the profile of the cams 182 and forcethe blades 166 and 172 to open against pressure of springs 188.

Inboard of the side walls 52 and 54 of the tank 42 there is provided atrip lever 184 having one end also mounted on the shaft 180. Each shaft180 is mounted in a plurality of bearings 181. The support blades 166and 176 are provided at their opposite ends with springs 188 as shown inFIGS. 18 and 19. The wiper blades 166 and 176 are spring loaded in theclosed position as shown in FIG. 18. As a magnetic frame 48 travels upthe ramp wall 60, the frame 48 contacts the trip levers 184 which opensthe wiper blades 166, 176. After the frame top has passed the triplevers 184, the blades 166, 176 close on the magnetic rods 130 of theframe 48 and wipe off the collected ferrous particulate. When the bottomend of the frame 48 approaches, the wiper blades 166, 176 protrusions orlower trip pins 152 on the frame 48 made for this purpose contact thetrip lever 184 and the blades 166, 176 again open to allow the bottom ofthe frame 48 to pass therethrough, with the ferrous materials removedfrom the frame 48 as a result of the wiping operation. It will beappreciated that the wiper cams 182 are attached to the trip levers 184through the shafts 180. When the trip levers 184 are rotated by themoving frame 48, the cam action forces the blades 166, 176 apart. Thewiper blades may be actuated by other means such as pneumatic cylinders.

As the frame 48 exits the wiper blades 166, 176 as shown in FIGS. 5 and6, it is necessary to reroute the bottom of the frame 48 from the lowerramp track 60 to the upper ramp track 98. This is accomplished by theuse of a switch track which consists of a stationary part 190, astationary upwardly inclined part or ramp 191 and a pivoted hinge partor door 192 pivotally connected to a switch guide track 194. A pivotconnection 193 is provided between track parts 192, 194. The switchtrack also includes a ramp 189 for the tubular guide pins 152 as theframe 48 moves upwardly.

As shown in FIGS. 14 and 15, as the magnetic frame 48 travels in thedirection of arrow A and after it has exited the wiper blades 166, 176,it moves up the ramp 60 where the pins 150 at the lower end of the frame48 engages the stationary upwardly inclined ramp 191 of the switch trackas shown in FIG. 15. The bottom end of the frame 48 then changesdirection and moves up the inclined switch track part 190 which isstationary as shown in FIGS. 16 and 17. At the upper edge of the switchtrack part 190, the pins 152 on the lower edge of the frame 48 engagethe movable pivoted track 192 and raises same away from the stationarytrack part 190 thereby creating an opening between the stationary part190 and the pivoted part 192 which permits the lower end of the frame 48to clear the stationary track 190. Thereafter, the pivoted track 192returns by gravity to its position engaging the stationary part 190 asshown in FIG. 17. As a result thereof, the frame 48 has cleared theopening and is on the other side of the moveable door 192. As the chains44, 46 continue to move, the frame 48 now travels in a reversedirection, in the direction of arrow B of FIG. 17. The frame 48 is nowguided by the pivoted door 192 and the track part 194 as it moves in thedirection of arrow B. Thus, the frame 48 follows the upper ramp track 98as the conveyor chains return to the main tank 42.

It is not necessary for the conveyor drive to operate continuously. Asthe frames 48 are conveyed through the tank 42, periodically a frame 48on the upper track 96 is positioned directly above the frame 48 on thelower track 92 as is shown in FIGS. 2, 3 and 4. Allowing the frames 48to dwell in this position is desirable in that it presents noalternative path for fluid to flow except through the magnetic gaps ofthe frame 48. Therefore, suitable controls may be used to allow theconveyer to stop in this desired position for long periods of time whilethe magnetic rods 130 attract the fluid borne particulate or ferrousparticles. Then, on a timed basis, the drive advances one frame throughthe wiper station 160 until the limit switch 200 is contacted to haltthe conveyor chains once again in this desirable position. Suitablerelay means may be provided to change the dwell time as required.

By increasing the length of the tank 42, many more frames 48 can besuspended in the flow providing a “multi-pass” effect. The frames 48travel the length of the tank 42 and the coolant is forced to flowthrough all the magnetic rods 130 located in the tank 42, not merely themagnetic rods 48 closest to the inlet as in the prior art.

The magnetic separator 40 is provided with a plurality of upper andlower tank baffles and side ramps. The upper tank baffles 202 areprovided in the space between the side walls 52, 54 and the ends of theframes 48 below the top track 96 and above the guide rail 102 as shownin FIG. 4. In addition, lower tank baffles 204 are provided in the spacebetween the side walls 52, 54 and the ends of the frames 48. Inaddition, a pair of side baffles 208 are also provided. Each baffle 208is a sloping plate which extends the entire length of the floor. Itsfunction is to provide a slope in order that particulate does not settlein this area since the frames 48 do not drag closely to the tank walls.The descriptor 204 does not touch the sloping plate baffle 208.

Thus, the present invention provides a new method and apparatus ofmagnetically separating ferrous particles from metal working coolantsand parts washing fluids. The magnetic rods are mounted in framessuspended between the conveyor chains in a manner allowing the frames toswivel and always hang vertically as the chain follows its path. Withsuch a construction, the fluid or liquid in the tank is forced to flowthrough all the gaps between the rods in the tank. Each gap isapproximately one half inch in width. The ferrous particles areattracted to the magnetic rods or tubes. Later the tubes are wiped cleanat the wiping station and the ferrous particles are collected andremoved from tank. The steel scraping edge at the bottom of each framecontacts the floor and ramp and drags out the settled non-magneticparticles or particulate from the tank.

1. A magnetic separator comprising: an elongated tank having a bottomwall, a pair of side walls connected to said bottom wall, a front wallconnected to said bottom and side walls at one end of said tank and aramp wall at the other end of said tank extending upwardly from saidbottom wall and in a direction away from said front wall to form anupwardly and outwardly inclined ramp having the edges thereof connectedto said side walls; an inlet provided in a wall of said tank fordirecting liquids containing ferrous particles and other particulateinto said tank; an outlet provided in a wall of said tank where theliquid after treatment exits said tank; a track system mounted in andextending lengthwise of said tank including a lower tank track, an uppertank track spaced above said lower tank track, a lower ramp track and anupper ramp track spaced above said lower ramp track; a pair oftransversely spaced apart endless conveyor chains movably mounted insaid tank and guided by said track system, said conveyor chainsdescribing an endless loop within said tank; a plurality oflongitudinally spaced magnetic frames in said tank, each frame extendingacross said tank between said side walls and having an upper end and alower end, with said upper end of each frame suspended from saidconveyor chains; each of said frames carrying a series of parallelmagnetic rods which are spaced apart to form magnetic gaps and throughwhich the liquid passes as the conveyor chains and frames traverse saidtank, with the ferrous particles in the liquid being attracted to anddeposited on said magnetic rods; the lower end of each frame beingprovided with a scraper edge that contacts the bottom and ramp walls ofthe tank when the frame is traversing the lower tracks to scrape theparticulate from the bottom and ramp walls and move the particulatetowards the other end of said tank where it is discharged; each frame asit leaves said lower tank track and enters said lower ramp track closelyfollows the inclination of said ramp as the frame travels up said ramp;wiper blades located near the upper end of said ramp, each frame as itis moved by said conveyor chains up said ramp engaging a trip leverwhich opens said wiper blades; each frame as it is moved by saidconveyor chains after the top thereof has passed said trip lever movingthrough the opening between said wiper blades, said wiper bladesthereafter closing on the magnetic rods of said frame to wipe and removethe collected ferrous particulate from the magnetic rods; the lower endof each frame as it is moved by said conveyor chains and approaches saidwiping blades causing a protrusion thereon to make contact with saidtrip lever resulting in the wiper blades opening to thereby allow thelower end thereof to pass through the openings; and a pivoted switchtrack which is normally closed interposed between said upper and lowerramp tracks, said switch track opening when contacted by each frame asit is swung upwards and forward, said switch track after each frame hascleared the opening falling back and forcing it to follow said upperramp and tank tracks.
 2. The magnetic separator as defined in claim 1,wherein said inlet is provided in said front wall near the bottom wall;and a baffle is mounted in said tank opposite said inlet, said baffleextending from one side wall of the tank to the other for reducing thevelocity of the incoming liquid and distributing the liquid evenlyacross the width of the tank.
 3. The magnetic separator of claim 1,wherein said outlet is located at the opposite end of the tank from saidinlet; and an overflow trough in said tank forming a dam, said troughbeing as wide as said tank, the fluid after treatment in said tankoverflowing said dam and exiting said trough through said outlet.
 4. Themagnetic separator of claim 1 wherein said lower tank and ramp tracksare provided with a guard vertically spaced in said tank and ramp tracksto assist in maintaining the conveyor chains on the tank and ramptracks.
 5. The magnetic separator defined in claim 1, wherein eachmagnetic rod includes a tube closed at opposite ends and having thereina plurality of bar magnets and pole pieces which are stacked inend-to-end abutting relationship.
 6. The magnetic separator as definedin claim 1, wherein said magnetic frames each comprises an elongatetubular member having a pair of outwardly facing end surfaces, saidtubular member forming the upper end of said frame and having alongitudinally extending axis, an elongated tube support spaced from andparallel to said tubular member and forming the lower end of said frame,a pair of longitudinally spaced side supports near the end portions ofsaid tubular member and tube support, said side support having edgesthereof connected to said tubular member and to said side supports, saidseries of magnetic rods comprising spaced tubes carried by said tubesupports between said side supports; and a plurality of bar magnets andpole pieces stacked in end-to-end abutting relationship in each of saidtubes between said tubular members and said tube support.
 7. Themagnetic separator of claim 6, wherein a tubular pipe extends throughsaid box tubular member of each frame, said pipe and having end portionsextending beyond the end surfaces of said tubular member, said tubularpipe having the ends connected to said conveyor chains.
 8. The magneticseparator of claim 6, wherein said scraper edge of each frame forms partof said tube support, said scraper edge being inclined at approximatelya 60° angle to the plane of said frame.
 9. The magnetic separator ofclaim 6, wherein said tube support is provided with a plurality ofnipples which are spaced apart, said nipples fitting into the inside ofthe tubes containing said bar magnetics and pole pieces.
 10. Themagnetic separator of claim 6, wherein a pair of guide pins are attachedto the lower edges of the side supports of each of said magnetic barframes.
 11. The magnetic separator of claim 6, wherein a pair of liftpins are attached to the lower edges of said tube support.
 12. Themagnetic separator of claim 6, wherein each frame includes an elongatedplate having a plurality of holes, with the holes spaced apart the samedistance as the spacing between said parallel tubes, said holespermitting said magnetic bars to be inserted into said tubes during theassembly of the frame.
 13. The magnetic separator of claim 1, whereinsaid track system is mounted along each of said side walls.
 14. Themagnetic separator of claim 13, wherein one of said endless conveyorchain moves in the track system along one side wall and the other ofsaid endless conveyor chains moves in the track system along the otherside wall.
 15. The magnetic separator of claim 1, wherein means areprovided for moving said conveyor chains in an endless path along saidtrack system.
 16. The magnetic separator of claim 15, wherein saidconveyor chains moving means comprising a pair of rotary sprocketsmeshed with said conveyor chains, one sprocket for each conveyor chain,a drive shaft connecting said sprockets, and power means having a driveconnection with said drive shaft.
 17. The magnetic separator of claim16, in which said tank has a liquid level and including means forsupporting said sprockets above said liquid level.
 18. The magneticseparator of claim 16, wherein said drive shaft is rotatable on ahorizontal axis that extends transverse to the side walls of said tank.19. The magnetic separator of claim 16, wherein said power means maybebe operated continuously or intermittingly where one of the magneticframes on the upper tank track is positioned directly above a frame onthe lower tank track thereby allowing the frames to dwell, withoutmoving, while allowing the liquid to flow through the magnetic gaps ofthe frames, with the magnetic rods attracting the ferrous particles. 20.The magnetic separator of claim 1, said magnetic frames are suspendedbetween said conveyor chains in a manner allowing said frames to swiveland to hang freely as the chains follows its endless path.
 21. Themagnetic separator of claim 1, wherein a pair of trip levers areprovided, each trip lever having a wiper cam attached thereto, said triplevers when rotated by the moving frame causing the cam to rotate andforce the wiper blades apart.
 22. The magnetic separator of claim 21,wherein springs are provided between each wiper blade and wiper cam forbiasing said wiper blades to the closed position.
 23. A magnetic barframe comprising: (a) an elongated tubular member forming the upper endof said frame and having a pair of outwardly facing end surfaces, saidtubular member having a longitudinally extending axis; (b) an elongatedtube support spaced from and arranged parallel to said tubular memberand forming the lower end of said frame; (c) a pair of longitudinallyspaced side supports near the end surfaces of said tubular member andtube support, said side supports having the edges thereof connected tosaid tubular member and to said tube support; (d) a plurality oflongitudinally spaced tubes carried by said tube support between saidside supports; and (e) a plurality of bar magnets and pole piecesstacked in end-to-end abutting relationship in each of said tubesbetween said tubular member and said tube support.
 24. The magnetic barframe of claim 23, wherein a tubular pipe extends through said tubularmember and having end portions extending beyond the end surfaces of saidtubular member.
 25. The magnetic bar frame of claim 24, wherein theouter end portions of said tubular pipe are attachable to endlessconveyor chains.
 26. The magnetic bar frame of claim 23, wherein anelongated scraper blade forms part of said tube support, said scraperblade having an edge which is inclined at approximately a 60° angle. 27.The magnetic bar frame of claim 23, wherein said tube support isprovided with a plurality of nipples which are spaced longitudinallyapart, said nipples fitting into the inside of said tubes.
 28. Themagnetic bar frame of claim 23, wherein a pair of guide pins areattached to the lower edges of said side supports.
 29. The magnetic barframe of claim 23, wherein a pair of lift pins are attached to said tubesupport.
 30. The magnetic bar frame of claim 23, wherein said frameincludes an elongated plate having a plurality of holes, said plateoverlying the upper ends of the tubes, said holes permitting saidmagnetic bars and pole pieces to be inserted into said tubes.